Adjustable silk screen device



Oct. 20, 1959 E. D. MOORE ET AL 2,909,116 ADJUSTABLE snx SCREEN DEVICEFiled Aug. 9, 1956 i I I I 4/ 43 Z6 4 l 'I I/ \\4J INVENTOR. 54,91. 0,M0035 RICH/4E0 J. ?Ff0 BY The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment of any royaltiesthereon or therefor.

The present invention relates to a silk screen device and moreparticularly to an adjustable device for accommodating diiferent sizesof workpieces that are to .be marked.

Various kinds and shapes of duplicating devices are known in theprinting art and many employ a'stenciling screen formed of open meshedsilk through which pigment is forced. The most common type of silkscreening device presently employed in the art consists of a worksupporting element and 'a silk screening element that is hingedlyconnected to the work supporting element. Heretofore, the worksupporting element has been grooved or contoured to accommodate oneparticular size and shape of workpiece and the two elements have beenpermanently hinged together. While this arrangement has been widely usedand has been quite successful, it has the main disadvantage of being avery costly item and when only a few items are to be marked or stenciledthe cost per unit of production is high.

The invention disclosed herein is for a silk screening device that isreadily adaptable to run small production quantities at a mosteconomical cost. The customary supporting element heretofore employed inlike devices is no longer required, and an electro-magnetic element isused to hold various sizes and shapes of workpieces. The silk screeninglid is hingedly connected to a platform which can be raised or lowered,and workpieces of various heights can be readily accommodated by thedevice.

It is therefore a general object of the present invention to provide asilk screening fixture that will accommodate multiple sizes and shapesof workpieces that are to be marked or painted.

Another object is to provide an adjustable fixture for silk screeningworkpieces wherein said workpieces are held in position byelectro-magnetic means.

Other objects and advantages of the present invention will be morereadily appreciated as the invention becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing wherein:

Figure 1 is a perspective view showing the complete invention; and

Figure 2 is a side view of a device constructed in accordance with thepresent invention.

Referring now to the drawing wherein like reference characters designatelike or corresponding parts throughout the several views, there is shownin Figure 1 a base plate 11 having four upstanding brackets 12-15,inclusive, attached thereto by means such as screws 16. A top flangeplate 17 is attached to the top of each upstanding bracket, and a screw18 is rotatably mounted between each flange plate 17 and the base plate11. A sprocket 19 is attached to each screw 18, and a continuoussprocket chain 21 engages each sprocket 19. A

Patented Oct. 20, 1959 shaft 22 is also rotatably mounted adjacent tobracket 12 between the top plate flange 17 and the base plate '11, and ahandwheel 23 and a spur gear 24 are attached to the end portions of saidshaft 22. Gear 24 engages with gear 25 that is attached to screw 18, andit can readily be understood that when handwheel 23 is rotated,

all four screws 18 will be rotatably driven thereby.

Referring now to Figures 1 and 2 of the drawing, there 'is shown arectangular frame 26 that is threadedly engaged at the four corners withthe four screws 18. It

should be obvious that by turning the handwheel 23, this frame 26 can beraised or lowered in height. As better shown in Figure 2, a hinge plate27 is slidably attached to frame 26, and can be locked in any desiredposition by means of locking screw 28. One-half of a pianotypeghinge 29is attached to hinge plate 27 and the mating half-hinge 31 is attachedto a silk screen frame 32 by means of hinge pin 33.

'The silk screen frame may be any conventional type well known in theart, and might consist of a wooden framework covered by a silk screen onwhich is formed the design desired to be printed. When it is desired tochange silk screen frames, the hinge pin 33 can be removed from the twohinge halves, thus separating the silk screen frame from the hinge plate27. Another frame can then be placed in position and, upon replacing thehinge pin, the newly inserted frame is ready for operation. As the hingeplate 27 is slidably adjustable along the frame 26, various sizes ofsilk screen frames can be accommodated and therefore savings in materialcan be had, as the frame need only be of the size as required by thedesign to be printed.

Referring again to Figure l of the drawing, it can be seen that amagnetic chuck 34 is attached to base plate 11 and fits within the frame26 so that there is clearance between the frame 26 and the chuck 34,thus permitting the frame 26 to be raised or lowered. The magnetic chuck34 might be of any conventional type well known in the art, and might beeither the permanent magnetor electro-magnetic type. The top surface ofthe magnetic chuck 34 serves as the work surface for mounting theworkpieces that are to be marked or painted. For purposes ofillustration, there are shown two small parts 35 and 36 which arepositioned between guide plates 37. The guide plates 37 can be made ofany suitable magnetic material, and of course their sizes and shapeswill be dependent upon the nature of the workpieces that are to bemarked. The illustration shown in Figure 1 is best suited fornon-magnetic workpieces such as nonmetallic terminal boards and thelike. These types of parts will not be affected by the magnetism of thechuck and can be removed therefrom without demagnetizing the chuck 34.Thus once the guide plates 37 are placed in the desired position thecurrent to the chuck 34 can be left on, thus assuring that the guideplates 37 will stay in the proper position throughout a production run.However, metallic parts could be marked equally well on the deviceherein described, as commercial demagnetizers are commonly employed withvarious magnetic chucks.

In operation, the half-hinge 31 on silk screen lid 32 is connected withthe half-hinge 29 on hinge plate 27 by means of hinge pin 33. The hingeplate 27 is then moved forwardly until the tang 38 on silk screen lid 32can be engaged with the slot 39 on locking bar 41. It can be seen thatthe front rail of the frame 26 is provided with a longitudinal slot 42and that locking bar 41 can be moved along this slot so that the tang 38will engage slot 39. A screw 43 is provided to lock the locking bar 41in a fixed position. The locking bar 41 is provided in order to morefirmly hold the silk screen lid in position so that on application ofthe ink or dye to the silk screen no movement will take place and thusblurring or smearing of the ink on parts 35 and 36 will be avoided.

The next step of the operation is to position a sample part 35 or 36 onthe magnetic chuck and then raise or lower frame 26 by means ofhandwheel 23 until the silk screen is properly positioned over thesample part. The guide plates 37 are then positioned so that the samplepart will be in the proper position to receive the design or letteringthat is to be applied. When the guide plates 37 are in proper position,the magnetic force of the chuck is applied and this force will then holdthe guide plates 37 in position. Once the frame 26 is adjusted in heightto accommodate a particular part no further adjustment is required for aproduction run involving that particular part, and thus a large quantityof parts can be readily marked or painted.

As illustrated in the drawing, two difierent parts are mounted on themagnetic chuck at the same time. Of course, the thickness or height ofthese parts should be substantially equal in order that the silk screenlid 32 can be properly positioned over these parts.

It can thus be seen that the invention disclosed herein readilyaccomplishes its objects and that in order to mark or paint differentdesigns, only the silk screen lid need be changed. This change can bemade very quickly as ,it merely entails unhinging one lid and hinginganother in place.

Obviously many modifications and variations of the present invention arepossible, and it should be understood that the foregoing disclosurerelates to only a preferred embodiment of the invention.

What is claimed is:

A silk screen device comprising, a base plate, a magnetic chuck attachedto said base plate, metallic holding means adaptable for positioning onsaid magnetic chuck parts to be silk screened, a plurality of bracketsattached to said base plate, a plurality of screws rotatably support bysaid brackets substantially perpendicular to said :base plate, arectangularly shaped frame threadedly attached to said screws, saidframe comprising front and back rails and two side rails, said frontrail having a longitudinal slot substantially the entire length thereof,the inside dimensions of said frame being larger than the outsidedimensions of said magnetic chuck whereby said frame is positionablearound said magnetic chuck, at least one locking bar slidably attachedto said front rail of said frame through said longitudinal slot, a hingeplate slidalbly connected to the two side rails of said frame andmovable in a plane parallel with the top surface of said base plate, anda silk screen lid hingedly connected to said hinge plate and having atang thereon adaptable for engaging said locking bar. 7

References Cited in the file of this patent UNITED STATES PATENTSLindley et a1 Nov. 16, 1897 1,840,073 Williams Jan. 5 1932

